> > Back to the subject; > I was not sure if this is a round engine or a long flat affair. if >it is round I would suggest a technique for an experimental approach. >Build a H2O2 gas generator with a flange on it's exhaust. Bolt on what >ever nozzles you want to test to this flange. This way you could get the >cat pack working as a separate issue. Also you could avoid having to >redo the details of this part every time you switch nozzels. Perhaps >since you would now have a standard flange on the nozzle side (to match >the gas generator flange) it would be wise to make a jig for a machine >tool (lathe if it is round) to cut setup costs in manufacturing. Having >the flange as a reference point would allow you to cut and paste "G" >code to give any fancy shape you might come up with in the nozzle.
This is the way we have done it, and it has been very worthwhile -- we have used the same catalyst pack on a half dozen different nozzles / combustion chambers. Another thing that was useful was to use a clamp ring to retain many of the chambers, under the principle that you should minimize the machining operations on the parts you are going to be experimenting with. That allowed us to have 0.5" narrower chambers, and not have to drill the flange holes for every one. For monoprop use, you can make reasonable arguments for flange-at-top vs flange-at-bottom (our early foam engines were flange-at-top), but for experimental biprop work, separate cat packs and nozzles makes a lot of sense. As we close in on our proper parameters, we are considering a combined biprop design that would save a lot of mass, but we will only do that after we have proven the concepts on a multi-part engine. John Carmack _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
